Content access transmission and communication systems, e.g., high speed data, audio and video content transmission systems, serve numerous users where each user has one or more devices (e.g., display devices, gateways, set top boxes or modems) which execute software. These devices often contain sophisticated and secure application software, for example, software to decode and process signals (e.g., at the user's location) in order to provide specific content or services to the user. It may be desirable to change the software code images executing at the user's locations in order to update the software, provide new services, and enhance existing services, etc. However, downloading secure software from a central facility to devices in the field presents risks, such as the risk of unauthorized code being loaded onto a device. For example, malicious users may attempt to load an authenticated secure application code image intended for one device onto other similar devices that should not receive the code image. Other malicious users may attempt to load a previous application code image onto a device in order to exploit known bugs in the previous software version. The complexity of securely downloading software is further compounded by the large number of devices that may be involved, and the different content and services that may be provided to each device.